GDViewer DisplayFromString

[rbsoft]

Hello,

I am using evaluating GDViewer with RealBasic and everything seems to be working very well. However, I have a problem that I hope you can help with:

When I load a PDF directly from a file there is no problem. However, when I load the PDF file contents into a string and try to use DisplayFromString I get a result of 13 and cannot open from string. Here is a code sample in RealBasic 2008:

Code: Select all

  Sub OpenPDF(f as folderitem)
  dim nState as integer
  dim tis as TextInputStream
  
  If f <> Nil then
    if f.Exists then
      call gdviewer1.SetLicenseNumber("Removed")
      tis = f.OpenAsTextFile
      'nState = GdViewer1.DisplayFromPdfFile(f.AbsolutePath) 'I commented out this line, which works and loads the pdf properly
      nState = GdViewer1.DisplayFromString(tis.ReadAll) 'here is where I have trouble, it returns 13 instead of 0
      tis.close
    Else
      msgbox "File Not Found."
    End if
  else
    quit
  end if
End Sub

Any help would be appreciated.

Thanks!

-Mike

[Loïc]

Hi Mike,

Please send a basic RB application embedding your code at esupport (at) gdpicture (dot) com.

We will download a trial version of RB to see what we can do.

With best regards,

Loïc

[rbsoft]

Hi Loïc,

No problem, I already sent it on Feb 5th.

-Mike

[rbsoft]

Excuse me, I misspoke. I only sent the PDF. I will send the code sample right now.

-Mike

[rbsoft]

I'm still waiting for a response on this, or some indication that you've received my file via email...

In the mean-time I have tested DisplayFromString by modifying your VB example (vb_sample.vbp ) so that the Load PDF button functions as follows:

Code: Select all

Private Sub Command20_Click()
Dim sExt As String
Dim strTemp As String 'holds one line
Dim strAll As String 'holds the whole file
Dim ffile 'file handle
Dim i As Long 'return value from DisplayFromString

   
   Me.CommonDialog1.Filter = "All Files (*.*)|*.*|PDF (*.pdf)|*.pdf"
   Me.CommonDialog1.ShowOpen
   If Len(Me.CommonDialog1.FileName) > 0 Then
      ffile = FreeFile
      Open Me.CommonDialog1.FileName For Input As #ffile
      While Not EOF(ffile)
      Line Input #ffile, strTemp
        strAll = strAll & strTemp 'read the whole file into strAll
      Wend
      Close #ffile
      'Me.GdViewer1.DisplayFromPdfFile (Me.CommonDialog1.FileName) 'removed for this test
      i = Me.GdViewer1.DisplayFromString(strAll) 'try to display from string
      MsgBox i 'returns error code 13
   End If
End Sub

This is the same result that I get with REALBasic: error code 13 - unknown image format. The PDF files open just fine when I use DisplayFromPDFFile so there is nothing wrong with the format.

I also tried outputting the string to a temporary PDF file and opening the PDF file in Acrobat Reader, which worked. So that tells me that the string in fact the correct format.

I can only conclude that there is a bug in DisplayFromString in REALBasic and Visual Basic, or there is something wrong with how the string is being passed.

-Mike

[Loïc]

Hi Mike,

Your vb6 code is incorrect. I suspect your RB code incorrect too.
I was not able to compile your RB project using latest RealBasic compiler...

Here the good way to load PDF from string in vb6:

Code: Select all

Private Sub Command19_Click()
   Call GdViewer1.DisplayFromString(Text2String("c:\test.pdf"))
End Sub

Public Function Text2String(strPath As String) As String
   Dim intFile As Integer
   Dim strTemp As String
   Dim lByteLen As Long
   Dim bytArray() As Byte

  intFile = FreeFile
  Open strPath For Binary As intFile
  lByteLen = LOF(intFile)
  ReDim bytArray(1 To lByteLen)
  Get intFile, 1, bytArray

  
  Text2String = StrConv(bytArray, vbUnicode)
  Close intFile
  Erase bytArray
End Function

Hope this helps.

Kind regards,

Loïc

[rbsoft]

Thanks, that works in VB. I'll see if I can convert it to RB.

[rbsoft]

Still having trouble with RB. Would it be possible to get a sample function for RB?

[Loïc]

Hi,

I don't understand how RB works with strings. You have more competence than me.

I suggest you to post the issue to the RB support. The goad is to store the content of a file in a string variable, then you will be able to call the desired function of GdViewer.

Kind regards,

Loïc

[rbsoft]

I appreciate your help so far.

Since you are the one who will be getting my $250 I don't think that a sample function in REALBasic is too much to ask for, especially since REALBasic is a development environment that your plugin specifically supports.

I will be purchasing immediately as soon I can get it to work, but it's taking a lot of my time trying to figure it out with no real samples for this function.

Thanks,

-Mike

[rbsoft]

I took the string values that were being sent to DisplayFromString from VB and RB and wrote them both out to a file. I found only one difference between the two files: the "Size" of the VB file is 2 bytes larger than the RB file.

Strangely, it does not affect the "Size on disk". Here is a screenshot:



Is VB or StrConv tacking on some kind of EOF marker that RB is not, or could it be there is a particular character that DisplayFromString is looking for in order to validate the format of the PDF file?

Interestingly, Acrobat Reader can open both files without any problems.

[rbsoft]

I found the problem that was causing discrepancies between the file sizes. Now I can load a simple PDF (4kb) in RB but not a larger, more complex one (1mb).

Do you know what exactly StrConv(bytArray, vbUnicode) is doing to the string? I need to replicate that in RB to get it to work.

[jpbro]

StrConv(BYTEARRAY, vbUnicode), converts the byte array to a Unicode (2 bytes per character) string. I don't think that this is the best approach if you already have your data in a byte array - maybe you should try using DisplayFromByteArray instead?

Unfortunately, I don't use RealBasic, so I can't help much more than that - if DisplayFromByteArray doesn't work, you will have to see if there is a way to convert your RB array/string into a Unicode string before using DisplayFromString.

[sanket]

Version:- GDViewer 5.xx.
Browsere:- IE11

I have binary data of the TIFF image, when I am using DisplayFromString() from javascript/Vbscript it's not at all working for me. Where as when I have used DisplayFromByteArray() from vbscript it's working. I dont want to use VBscript as it is not supported in IE11. Is there any way to put image on viewer from binary data???